Heat treating hydrocarbons at an elevated temperature



Patented Jan. 10, 1933 UNITED STATES PATENT OFFICE AL'WIN MITTASC'H, OF MANNHEIM, RUDOLF WIETZEL, OF LUDWIGSHAFEN-ON-THE- RHDTE, AN'D CONRAD PFAUNDLER, OF OPPAU, GERMANY, ASSIGNORS TO I. G. EABBEN-INDUSTRIE AKTIENGESELLSGHAFT, OF FRANKFORT-ON-THE-MAIN, GER- MANY, A CORPORATION OF GERMANY HEAT TBEATING-HYDROCARBONS AT AN ELEVATED TEMPERATURE No Drawing. Application filed March 11, 1927, Serial No. 174,694, and in Germany March 13, 1926.

It has been shown elsewhere that in the conversion of hydrocarbons of high boiling point into others of lower boiling point at high temperatures, precaution should be taken to prevent the hydrocarbons from coming into contact with materials which cause the deposition of coke and soot.

We have now found that this method of working may also be advantageously adopted in operations conducted with gaseous or liquid hydrocarbons, or mixtures containing same, for example with brown coal tar oils, suspensions of coal and the like, at elevated temperatures. For example, in transforming gaseous hydrocarbons into liquid hydrocarbons, it is important that the gaseous or vapors, so long as they are at an elevated temperature, and therefore before, during and afterthe reaction, should only come in contact with such materials as do not produce a deposit of soot. This method of working is also valuable in other cases, as for example in distilling, or in dehydrogenating hydroaromatic compounds, in extracting coaly materials with or without the aid of pressure, in the hydrogenation of unsaturated hydrocarbons, for example of ethylene to ethane. The

advantages of this method of working are particularly apparent in operating with liquid hydrocarbons under pressure. The said method may also be applied, for example, in the distillation of hydrocarbon mixtures, followed by catalytic treatment of the vapors in the presence or absence of reactive gases. Hence, substances (free iron in particular) leading to deposition of soot should be absolutely excluded from the hot parts of the apparatus. It should however be noted that iron in the form of alloys such as steels containing. chromium, manganese, or tungsten, and the like does not exhibit any injurious action.

According to the present invention, the substances coming-into consideration as materials for the inner walls of the reaction vessels, for feed and efiluent pipes, heat exchanging devices (if any), and the like, are

ite, such as coal, or the like. The use of catalysts for example in the transformation of gaseous hydrocarbons into liquid hydrocarbons, is not essential, but if they are used, it has been found that all such substances are suitable as do not lead to the production of any appreciable deposition of coke or soot (if at all) namely the materials mentioned above, or silica, pumice, barium carbonate, charcoal impregnated with barium salts, boron, tungsten and the likeeither alone or on suitable carriers or the like, or in conjunctionwith other compounds.

What we claim is:

1. In processes in which hydrocarbons are subjected to a heat treatment at elevated temperatures, the step of confining said hydrocarbons while at said elevated temperatures, with a material consisting pf an alloy composed of iron and silicon.

2. In processes in which-hydrocarbons are subjected to a heat treatment at elevated temperatures, the step of carrying out such process in a vessel the inner surfaces of which consist of an alloy composed of iron and silicon. 75

3. In converting gaseous hydrocarbons into liquid hydrocarbons, the step of confining said hydrocarbons, in a vessel having a lining of a material consisting of an alloy composed of iron and silicon.

4. In the distillation of a hydrocarbon, the step of confining said hydrocarbon, in a vessel having a lining of a material consisting of an alloy composed of iron. and silicon.

5. In processes in which hydrocarbons are subjected to a heat treatment at elevated temperatures, the step of carrying out such process in a vessel the inner surfaces of which consist of a material selected from the class consisting of cobalt and an alloy composed of iron and silicon.

In testimony whereof we have hereunto set more particularly ferro-silicon, cobalt and the of graphite like, with or without a coating h h wit grap and also other materials coate 

